Apparatus for making soap and removing glycerin therefrom



y 15, 1941- B. H. THURMAN 2,249,675

APPARATUS FOR MAKING SOAP AND REMOVING GLYGERIN THEREFROM Original Filed May 21, 1935 Mom W136 Patented July 15, 1941 APPARATUS FOR MAKING SOAP AND REMOVING GLYCERIN THEREFBOM Benjamin H. Thurman, Bronxville, N. Y., assignor to Refining, Inc., Reno, Nev., a corporation of Nevada Original application May 21, 1935, Serial No. 22,555. Divided and this application December 29, 1938, Serial No. 248,354

1 Claim.

My invention relates to an apparatus for the manufacture of soap, and more particularly to an apparatus in which glycerin may be removed from the soap after saponification of its constituent fats. 3 l

Soap is produced by the saponification of fats by suitable reagents, and for all purposes herein the term fat" is defined as including all those fats, oils, and other substances which may be used in soap manufacture, including, for example, animal fats, vegetable oils and fats, and fish oils.

The term reagent as used herein includes all those substances which are adapted to produce a saponification of fats, such as, for example, caustic potash or causic soda in aqueous solution.

The term purifying agent as used herein is defined as including all those substances which are adapted to remove impurities from fats or soaps when used in connection with the hereinafter described process.

It is a primary object of my invention to provide an apparatus whereby fat may be saponified with a reagent to produce reaction products including soap and glycerin, the glycerin being then separated from the soap, and the soap being finished independently of the glycerin.

It is a further object of my invention to provide an apparatus whereby raw fats or fats in a partially purified state may be saponified with a reagent to produce soap and glycerin, the glycerin then being separated from the soap, and the soap being purified independently of said glycerin.

Another object of my invention is to provide an apparatus whereby raw fats or fats in a partially purified state may be saponified with a reagent to produce soap and glycerin, the glycerin then-being separated from the soap, and the soap being purified independently of the glycerin and subsequently finished so as to have a desired moisture content. 1

Another object of my invention is to provide an apparatus whereby soap may be made in a substantially continuous process, including the steps of continuously saponifying a fat with a 'reagent to produce reaction products including soap and glycerin, continuously removing the glycerin from said reaction products, and continuously finishing the soap independently of said glycerin.

A still further object of my invention is to provide an apparatus whereby soap may be made in a substantially continuous process, including the steps of continuously mixing a raw or partially purified fat with a reagent, continuously saponifying the mixture of fat and reagent to produce soap and glycerin, continuously removing the glycerin from the soap so that it may be recovered in a relatively pure state, purifying the soap, and continuously passing the purified soap through a moisture content control device to produce a finished soap having a predetermined moisture content.

Further objects and advantages of my invention will be evident from'the following disclosure and the claim.

Referring to the drawing, which shows an apparatus which I prefer to use in the practice of my invention but which is for the purpose of illustration only, the figure is a diagrammatic general assembly view in elevation of the apparatus, a portion of this apparatus being shown in section.

In the drawing, I show a mixing apparatus l0, a primary heating means 20, a separating means 30, a primary condensing means 40, a secondary condensing means 50, a .purifying means 60, a secondary heating means 80, and a finishing chamber 90.

The mixing apparatus I0 consists of an alkali pump H and a fat pump 12, the pump 12 being driven by a suitable motor l3 and the pump H being driven from the pump l2 through a variable speed transmission Hl, which may be made in the form of a speed changing gear. The fat which it is desired to convert into soap is taken from a fat tank I6 and is pumped into a. mixer H by the pump I2. An alkali tank [8 contains an aqueous solution of a saponifying alkali or reagent, such as caustic soda in water, the pump II taking the aqueous solution or reagent from the :tank I8 and pumping it into the mixer ll.

The mixed fat and reagent pass through a pipe IE to a coil 2| of the primary heating means 20.

The primary heating means 20 is comprised of an outer shell 23, within which the coil 2| is positioned, and has a burner 24 adapted :to be supplied with fuel through a valved fuel pipe 25. Gas, oil, or any other suitable combustible material may be used as fuel in the burner 24, this fuel being ignited at the burner, and the hot products of combustion passing upwardly inside the shell 23 and supplying heat to the coil 2|. In the mixer H, the pipe l9, and .the coil 2| a reaction takes place in which part or all of the fat is saponifled to form soap, glycerin, water vapors, residue fats, and other by-products, hereinafter termed the "reaction products." The reaction products are delivered through a pipe 26 having a. pressure gauge 21 and a thermometer 26 therein, to the separating means 36. A valve 29 is also placed in the pipe 26, so :that the amount of reaction products fiowing therein and the pressure thereof may becontrolled as desired.

The separating means 36 is comprised of an outer shell 3|, which is preferably of air-tight construction, into which the pipe 26 extends, the end thereof being provided with a nozzle means 32 which may be of any suitable construction and preferably has a restricted orifice therein through which the reaction products flowing in the pipe 26 may be ejected downwardly. Communicating with the lower end of the shell 3| is a valve means preferably in the form of a star valve 33 to permit removal of the reaction products therefrom, it being connected to a pipe 35. A pipe 34 also connects with the pipe 35 so that water or other liquid may mix with the' reaction products to render them sufficiently fiuid to be pumped through the pipe 35 by a pressure pump 36 driven by a motor or other source of power 31. A pipe 38 leads from the upper end of the shell 3| to the primary condensing means 46.

The primary condensing means 46 consists of a shell 4| having intermediate heads 42 between which cooling water is circulated from a valved pipe 43'to a drainage pipe 44. Tubes 45 extend between the heads 42 so that vapor from the pipe 38 can pass upwardly through the tubes and be delivered to a vapor conduit 46. Any liquid condensed in the tubes 45 passes downwardly through an exit pipe 41, which is preferably approximately thirty-five feet in length, the lower end of the exit pipe being at all times submerged in liquid carried in a glycerin tank 46 which acts as a receptacle for the glycerin or other liquid condensed by thfirimary condensing means 46.

Vapor in the vapor conduit 46 is delivered to the lower end of the secondary condenser means 56, which is similar in construction to the primary condenser means 46, it being cooled by water delivered from a valved pipe which escapes or is forced out through a drain pipe 52. Any liquid condensed in the tubes of the secondary condensing means 56 passes into an exit pipe 53, which preferably extends downwardly approximately thirty-five feet and has its lower end at all times submerged in water carried in a water tank 54. tanks 48 and 54 are at all times open to atmospheric pressure, each of the tanks 48 and 54 being of sufficient capacity to hold more than the entire contents of the pipes 41 and 53 respectively.

Leading from the upper end of the secondary condensing means 56 is a pipe 56 having therein an air pump 51 driven by a suitablepower source such as a motor 58. The air pump 51 is of any convenient construction capable of withdrawing air and vapor from the secondary condensing means 56 and establishing and maintaining a high vacuum therein.

The pipe 35 from the separating means 36 is connected through inlet pipes 65 and valves 6| with a plurality of kettles or tanks 62 which comprise the purifying means 66. Although in the drawing I show three kettles 62 connected to the pipe 35, it is to be understood that any desired number of kettles may be connected in like manner without departing from the spirit of my invention, and in practice it may be desirable to use either one large kettle or a large number of smal] kettles. Likewise, in the drawing all the kettles are shown to be of similar construction,

The surfaces of the liquids in the soap pipe 61 having a soap pump 66 therein driven by a motor 69. The outlet pipes 63 are also connected through valves 16 to a waste pipe H through which brine, impurities, and other substances may be drawn off from the kettles 62 and thereby separated from the purified soap. The soap pump 66 is preferably a gear or screw pump capable of handling the purified soap coming from the kettles 62 and forcing it through the soap pipe 61 and delivering it to a coil 6| of the secondary heating means 66.

The secondary heating means 66 consists of an outer shell 62, housing the coil 6|, and a burner 63 supplied with fuel through a valved fuel pipe 64. Any suitable fuel may be used in the burner 83, although I prefer to use gas or oil which may be supplied from the same source as that which supplies the burner 24, this fuel :being ignited at the burner and the hot products of combustion passing upwardly inside the shell 62 and supplying heat to the coil 6|. In the coil 6| the purified soap is heated to a desired temperature and is delivered through a pipe 65, having a pressure gauge 66 and a thermometer 61 therein, to a nozzle 9| in the finishing chamber 96.

The finishing chamber 96 consists of a shell 92 within which the nozzle 9| is positioned. The nozzle 9| is preferably comprised of a metal member having a constricted orifice through which the soap must pass, and it may be similar in construction to the nozzle 32. A suction blower 93 is connected to the shell 92 so that air and steam may be exhausted therethrough from the finishing chamber 96 as desired, and a valve 94 is placed in the lower end of the chamber so that the finished soap may be withdrawn therethrough from the chamber. A valved vent pipe 95 is connected to the lower end of the shell 92, so that air or other drying medium may be drawn through the finishingchamber 96 to dry the soap therein if desired.

The operation of my process will be better understood if the functions of the various pieces of apparatus above described are more fully ex-.

plained. Other apparatus which will perform the same function can, of course, be substituted without departing from the spirit of my invention.

The function of the pumps II and I2 is merely to pump fat and alkali into the mixer H in predetermined proportions, and to pump the resulting mixture into and through the coil 2| so as to build up any desired pressure in the primary heating zone formed by the primary heating means 26.

The primary heating means 26 is provided to heat or saponify the mixture of fat and alkali passing therethrough, which is performed by the transference of heat from the combustion products of the burner 24 through the wall of the coil 2| to the material flowing therein. The valve.-.

29 is provided in the pipe 26 to restrict the flow of reaction products in the pipe as desired, or to build up a back pressure in the heating zone of the primary heating means 28, which may be indicated on the pressure gauge 21.

The function of the separating means 30 is to provide a vaporizing space in which water and glycerin vapors may separate as a mixed vapor from the soap which may emerge from the orifice of the nozzle 32 at considerable velocity in the form of a jet. The soap settles in the form of dry, partially dry, or melted particles, passes through the star valve 33, and is mixed with water or other liquid from the pipe 34, which mixture is delivered through the pipe 35 by the pressure pump 36 to the purifying means 60. The pump 36 also acts to mix more completely the liquid from the pipe 34 with the soap.

The primary condensing means 40 is provided to condense the glycerin from the mixed water and glycerin vapors separated from the soap in the separating means 30, the glycerin running down as a liquid and being delivered through the pipe 41 to the glycerin tank 48.

The function of the secondary condensing means 50 is to condense the water from the water vapor or steam delivered through the conduit 46. The water so condensed is delivered through the pipe 53 to the tank 54.

The pump 51 is adapted to operate to establish and maintain a partial vacuum in the primary condensing means 48, the secondary. condensing means 50, and the vaporizing space in the airtight shell 3| of the separating means 30. This function is accomplished by the pump by the constant removal of air, gas, or vapor passing through the secondary condensing means 58.

The function of the purifying means 68 is to remove from the soap undesirable impurities,

such as, for example, coloring or odoriferousmatter. This is accomplished by the addition of brine or other purifying agent through the pipes 64 to the soap in the kettles 62. The brine reacts with the soap to remove from the soap impurities or other undesirable substances which V may be removed through the waste pipe H.

-The soap pump 68 is adapted to withdraw purified soap from the kettles 62 and to pump it into and through the coil 8| of the secondary heating means 80.

The function of the secondary heating means 80 is to heat the soap, which is accomplished in the form shown by the transference of heat from the combustion products of the burner 83 through the wall of the coil 8| to the soap flowing therein.

The function of the pressure gauge 86 and the thermometer 81 is to indicate the pressure and temperature of the soap leaving the secondary heating means 80, so that the pressure and temperature thereof may be controlled as desired by adjustment of the amount of fuel gas admitted to the burner 83 through the valved pipe 84 or by any other suitable means.

The function of the finishing chamber 90 is to provide a vaporizing space in which water or other liquid may be separated from the soap which may emerge from the constructed orifice of the nozzle that considerable velocity in the form of a jet. The soap settles in the form of dry or partially dry particles in the bottom of the shell 92, from which it may be withdrawn through the valve 94. The suction-blower 93 is provided to aid the vaporization of the water or other liquid in the finishing chamber by establishing and maintaining a low pressure in the chamber, and to remove such water or liquid vapor from the chamber. The blower 93 is also adapted to draw air or other drying medium through the chamber 98 when the valve in the pipe 95 is open to assist in the drying operation.

The method of operation is as follows:

The tank [6 is filled with the saponifiable fat which it is desired to convert into soap and which may contain undesirable foreign matter or coloring, this fat being heatedby any suitable heating means, if necessary, to a point at which it is liquid. The tank I8 is filled with an aqueous solution of a reagent or saponifying alkali, such as, for example, a solution of caustic soda in water. The fat is pumped into the mixer I! by the pump l2, and the reagent or alkali is pumped into the mixer H by the pump II. The variable speed transmission l4 may be adjusted so that l the proportion of alkali supplied to the mixer I1 is onlyslightly in excess of that theoretically necessary to completely saponify the fat.- The pumps H and I2 may be piston pumps but should be of such type that they can pump against several hundred pounds per square inch pressure. Themixture of saponifying alkali and saponifiable fat is delivered by the pumps II and I2 through the pipe I 5 to the coil 2| of the primary heating means 20 and is heated therein by the combustionproducts from the burner 24.

In the mixer H, the pipe l9, and the coil 2| a reaction. takes place between the saponifying alkali and the saponifiable fat, and reaction products including soap and glycerin are formed. The reaction products, of course, may also contain impurities and other substances. Sufiicient heat is supplied to the mixture in the coil 2| to raise the temperature of the reaction products passing through the pipe 26 to a point at which the reaction proceeds rapidly, which temperature is indicated on the thermometer 28. The pressure in the pipe 25 is indicated by the gauge 21. The soap and gylcerin passing through the pipe 26 may contain matter which it is desired to remove by purification, such as, for example, coloring or odoriferous matter, although some purification of the fat and soap may take place during the saponification of the fat in the coil 2|.

The reaction products are delivered through the pipe 26 and the valve 28 and ejectedin the form of a jet from the nozzle 32 in the separating means 38. Due to the high temperature of the reaction products when ejected from the nozzle 32, part or all of the water, glycerin, and any other fluids contained therein are flashed into vapor in the separating means 38, the vaporization being aided by the partial vacuum maintained in the separating means by the air pump 51. Sufficient heat may be supplied by the burner 24 to maintain the temperature of the reaction products passing through the pipe 28. as indicated by the thermometer 28, above the boiling point of glycerin at the absolute pressure indicated on the pressure gauge 2! or at the pressure existing in the separating means 38. The vacuum in the separating means 30 causes the mixed vapors of water, glycerin, and other liquids separating from the soap therein to pass through the pipe 38, and then successively through the primary condensing means 48 and the secondary condensing means 50. During the passage of the vapors through the condensing means, the glycerin vapor is condensed in the primary condensing means 40 and collected in the tank 48, and the water vapor is condensed in the secondary condensing means 58 and collected in the tank 54. Although I have shown two condensers, it is to be understood that I do not intend to be limited thereby, since it may be desirable to use a greater or less number of condensers depending upon the accuracy of distillation desired or upon the number of liquids desired to be con densed. Likewise, any suitable form of condenser, glycerin tank, or water tank may be used without departing from my invention.

The soap which is ejected from the nozzle 32 contains little or no water or glycerin and settles to the bottom of the shell 3|. The soap then passes through the star valve 33 and is mixed with water or other liquid from the pipe 34. The mixture of water from the pipe 34 and the soap in the lower end of the shell 3| renders the soap sufliciently liquid to be pumped from the shell through the pipe 35 by means of the pump 35, from which it is delivered to the purifying means 50.

One of the valves 6| is opened, and the remaining reaction products, of which soap is the principal constituent, which have been mixed with water in the pipe 35, are permitted to pass into one of the kettles 62. The outlet valves 55 and 10 are closed, and the kettle is filled to a desired point, at which time the inlet valve 6! of the filled kettle is closed, and the reaction products in the pipe 35 are then conducted to another kettle which is filled in the same manner. By providing a sufilcient number of kettles 62, and by replenishing the supplies of fat and reagent in the tanks l and I8 as becomes necessary, the saponification operation in the coil 2| and the separation of the water and glycerin vapors in the separating means 30 may be conducted continuously, the reaction products in the pipe 35 being conducted to the kettles in sequence. It is to be understood that several kettles may be filled at a time without departing from the spirit 01' my invention, and that although I prefer to operate my process continuously by filling the kettles in sequence, an alternative method of operation is to fill the kettles simultaneously, or nearly so, and to conduct the saponification and separation only intermittently to provide a process in which the reaction products are made, the water and glycerin vapors separated from the soap, and the soap purified in batches.

A purifying agent, such as brine, is passed into the kettle 62 through the pipe 64, and this may be done before, during, or after the kettle is filled with the reaction products, as desired. ,After the brine or other purifying agent is mixed with the reaction products in the kettle 52, a reaction takes place, often termed "salting-out" in the trade, during which the impurities settle to the bottom of the kettle together with the brine or other purifying agent. When the salting-out op eration is completed, the brine and impurities are drawn off from the kettle 52 by opening the valve I0 and allowing them to be removed through the waste pipe II, and the valve 10 is then closed. The valve 66 is then opened, and the purified soap may then be pumped out of the kettle 62 through the pipe 51 and to the coil ll of the secondary heating means by means of the soap pump 63,

In the coil 8| the temperature and pressure of the purified soap is raised, and it is then delivered through the pipe to the nozzle 3| of the finishing chamber 90. The soap emerges from a constricted orifice in th nozzle 9| in the form of a high velocity jet containing steam and particles of soap. The soap is thrown down violently to the bottom of the separating chamber 30 due to the velocity of the jet, and in its passage through the chamber the steam escapes therefrom, being withdrawn from the chamber by the suctionblower 93. The soap, having a desired water content, is collected in the bottom of the separating chamber and is withdrawn therefrom as desired through the valve 94.

It will be clear that by providing a suflicient number of kettles 62, and by purifying their contents in sequence, a continuous flow of purified soap can be maintained in the pipe 51. As soon as one kettle has been emptied of its purified soap through the pipe 61, another kettle outlet valve 66 may be opened, and the purified soap of its kettle can be drawn off through the pipe 51. Of course, as soon as one kettle is emptied, its valve 56 is closed, its inlet valve BI is opened, and it is again filled with unpurified reaction products which are purified as described hereinabove. This provides a continuous soap making process.

By regulating the temperature and pressure in the coil 8| of the secondary heater 80 by controlling the amount of heat supplied thereto by the burner 83 or otherwise, the soap collected in the finishing chamber can be given anydesired water content.

This is a division of my application Serial No. 22,555, filed May 21, 1935.

I claim:

In an apparatus for making soap, the combination of: a receptacle for receiving a mixture of soap and glycerin and means for maintaining heat sufllcient to vaporize said glycerin and to produce an anhydrous molten soap; means for withdrawing a stream of said soap from said receptacle; a plurality of purifying devices; means selectively delivering the soap from said separating means to said purifying devices to form a plurality of batches; means for adding a purifying agent to said purifying devices to purify said batches; heating means; means selectively withdrawing soap from said purifying devices and delivering this purified soap as a continuous stream to said heating means; and finishing means receiving the heated soap from said heating means for controlling the moisture content of said soap.

' BENJAMIN H. THURMAN. 

